A particular type of inflatable vehicle occupant restraint is commonly referred to as an air bag. An air bag is stored in a vehicle in a folded, uninflated condition at a location adjacent to the vehicle occupant compartment. When the vehicle experiences a collision, inflation fluid is directed to flow from a source of inflation fluid into the air bag. The inflation fluid inflates the air bag from the folded, uninflated condition to an unfolded, inflated condition in which the air bag extends into the vehicle occupant compartment.
When the air bag is inflated into the vehicle occupant compartment, it restrains movement of an occupant of the vehicle. The air bag thus helps to restrain the occupant from forcefully striking parts of the vehicle as a result of the collision. The force with which the air bag restrains the occupant is determined in part by the configuration and location of the air bag relative to the occupant as the air bag unfolds and moves into the vehicle occupant compartment.